This article attempts a fresh analysis of the supposed ornamental nature of medical institutions in Imperial Brazil (1822-1889). The institutions in question were active in the production and validation of scientific knowledge relating to health both public and private in the Empire. In contrast to interpretations which explain medical and hygienic thinking in terms of the immediate interests of dominant elites —forging a medical conscience “from the outside”— the article seeks to highlight the socio-professional dynamics mobilised for the validation and control of medical knowledge according to the same standards of proof prevailing in European hygienic and anatoclinical thought. It is argued that the social position occupied by the Imperial Academy of Medicine was built on meritocratic criteria. It was not the titled nobility which accredited scientific opinion or evidence, but rather the ability to reason in accordance with established scientific standards.